Transmission Theory Of Array-waveguide Grating--A New Study Method

Array waveguide grating(AWG) Multi/demultiplexer has being continually developed since 1970s. And some AWG have been made to approach the stage for utility. In this thesis, the AWG's transverse-mode parameter and its eigen equation as well is analyzed based on the periodic waveguide method. The results show that, as for the single-mode transmission, the dispersionrelations yet include space-dispersion (k dispersion) whichrelates to angular spectrum of fields of in-waveguide, in addition to the material- dispersion and the waveguide-dispersion. A perturbation method by tight-binding approximation which provide the relation of phase constant and angular spectrum of fields of in-waveguide is presented. The strip width of phase constant can be given. On the other hand, the group delay-timedue to the k dispersion in single-mode transmission can also beestimated. When AWG regarded as space unchanged linear system, an analytical solution of out-waveguide field is obtained by using the impulse response function. The crosstalk transformation on account of apertometer and waveguide spacing is also obtained by numerical calculation.